A107 Weather Reports

Question Answer
any given volume of air includes Nitrogen=78%Oxygen=21%Argon, carbon dioxide and other trace gasses=1%
4 distinct layers from smallest to largest troposphere, stratoshphere, mesosphere, thermosphere
most weather happens in? troposphere: sea level to 20,000 ft
what does temp do as you go up in tropsphere decreases 2degreee Celsius every 1,00ft
(4) characteristics of a warm front Warm, humid air moves to replace a body of cold airAs warm air is lifted, temp drops and condensation occursSummer months = ThunderstormsLight to moderate precipitation probable
(4) characteristics of a cold front Cold, dense and stable air advances to displace a body of warmer airStays close to the ground, acts like a snow plowRapidly ascending air causes temp to decrease suddenly and formation of cloudsCirriform and towering cumulus
low clouds are? and include up to 6,500 ft and include stratus stratocumulus and nimbostratus
medium clouds and include 6,500-20,000 ft and include altostratus and altocumulus and can produce moderate icing
high clouds and include above 20,000 ft and include cirrus cirrostratus and cirrocumulus
clouds with extensive vertical development do what? develop into thunderstorms
what are the 3 stages of a thunderstorm? Cumulus stage – lifting actionMature stage – most violent timeDissipating stage – downdrafts spread out
thunderstorm hazards (4) Updrafts and downdraftsLarge hailLighteningTornadoes
temps increase slightly with altitude in an anamoly called temp inversion
what is the lapse rate 2 degrees Celsius every 1,000 ft
what are 2 characterisitcs of a windshear wind changes of 180 degrees and 50 kts or more
2 characteristics of a microburst occur within 1,000 ft of ground and within 1 mile horizontally, create downdrafts of 6,000ft/min
hourly weather observation by a person or automated equipment. METAR
3 things required to change a SPECI wind change of atleast 45 degrees in 15 minutes with a steady speed of 100 kts or more, thunderstorm forms, clouds obscuring things below 1,000 ft AGL
METAR is taken when? at end of each hour 45-60
wind Is reported variable if 2 conditons occur wind direction varies more than 60 degrees, more than 6 kts
max. reported vis 10SM
the greatest horizontal visibility observed throughout at least half the horizon circle, and is not necessarily continuous. prevailing vis
is the distance over which a pilot of an aircraft on the center line of the runway can see the runway surface markings delineating the runway or identifying its center line. runway visual range RvR
in terms of weather – = and + = -light, + heavy
is a concise statement of the expected meteorological conditions at an airport during a specified period (usually 24 hours) TAF (terminal aerodrome forecast)
obscurations to vision will be forecast whenever the prevailing vis is forecast to be ________– less than 6 statute miles
temp in air must become cool to be saturated dew point
celing =` lowest broken or overcast layer of clouds